[dpdk-dev] [PATCH v2 08/16] fm10k: add Vector RX scatter function

[Chen, Jing D]

Hi, Steve,

Best Regards,
Mark


> -----Original Message-----
> From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Chen, Jing D
> Sent: Tuesday, October 27, 2015 1:44 PM
> To: Liang, Cunming; dev at dpdk.org
> Subject: Re: [dpdk-dev] [PATCH v2 08/16] fm10k: add Vector RX scatter
> function
> 
> Hi, Steve,
> 
> Best Regards,
> Mark
> 
> 
> > -----Original Message-----
> > From: Liang, Cunming
> > Sent: Tuesday, October 27, 2015 1:28 PM
> > To: Chen, Jing D; dev at dpdk.org
> > Cc: Tao, Zhe; He, Shaopeng; Ananyev, Konstantin; Richardson, Bruce
> > Subject: Re: [PATCH v2 08/16] fm10k: add Vector RX scatter function
> >
> > Hi,
> >
> > On 10/22/2015 5:44 PM, Chen Jing D(Mark) wrote:
> > > From: "Chen Jing D(Mark)" <jing.d.chen at intel.com>
> > >
> > > Add func fm10k_recv_scattered_pkts_vec to receive chained packets
> > > with SSE instructions.
> > >
> > > Signed-off-by: Chen Jing D(Mark) <jing.d.chen at intel.com>
> > > ---
> > >   drivers/net/fm10k/fm10k.h          |    2 +
> > >   drivers/net/fm10k/fm10k_rxtx_vec.c |   88
> > ++++++++++++++++++++++++++++++++++++
> > >   2 files changed, 90 insertions(+), 0 deletions(-)
> > >
> > [...]
> > > +
> > > +/*
> > > + * vPMD receive routine that reassembles scattered packets
> > > + *
> > > + * Notice:
> > > + * - don't support ol_flags for rss and csum err
> > > + * - nb_pkts < RTE_IXGBE_DESCS_PER_LOOP, just return no packet
> > > + * - nb_pkts > RTE_IXGBE_MAX_RX_BURST, only scan
> > RTE_IXGBE_MAX_RX_BURST
> > > + *   numbers of DD bit
> > In order to make sure nb_pkts > RTE_IXGBE_MAX_RX_BURST, it's
> necessary
> > to do RTE_MIN().

My bad. You indicates nb_pkts should be less or equal than RTE_IXGBE_MAX_TX_BURST.
I'll change accordingly.

> 
> I'll remove the improper comments. In func fm10k_recv_raw_pkts_vec, it
> will use
> nb_pkts as index to iterate properly.
> After then, below func will use actual received packet size nb_bufs as index
> to iterate.
> So, I think RTE_MIN() is not necessary?
> 
> > > + * - floor align nb_pkts to a RTE_IXGBE_DESC_PER_LOOP power-of-two
> > > + */
> > > +uint16_t
> > > +fm10k_recv_scattered_pkts_vec(void *rx_queue,
> > > +				struct rte_mbuf **rx_pkts,
> > > +				uint16_t nb_pkts)
> > > +{
> > > +	struct fm10k_rx_queue *rxq = rx_queue;
> > > +	uint8_t split_flags[RTE_FM10K_MAX_RX_BURST] = {0};
> > > +	unsigned i = 0;
> > > +
> > > +	/* get some new buffers */
> > > +	uint16_t nb_bufs = fm10k_recv_raw_pkts_vec(rxq, rx_pkts, nb_pkts,
> > > +			split_flags);
> > > +	if (nb_bufs == 0)
> > > +		return 0;
> > > +
> > > +	/* happy day case, full burst + no packets to be joined */
> > > +	const uint64_t *split_fl64 = (uint64_t *)split_flags;
> > > +	if (rxq->pkt_first_seg == NULL &&
> > > +			split_fl64[0] == 0 && split_fl64[1] == 0 &&
> > > +			split_fl64[2] == 0 && split_fl64[3] == 0)
> > > +		return nb_bufs;
> > > +
> > > +	/* reassemble any packets that need reassembly*/
> > > +	if (rxq->pkt_first_seg == NULL) {
> > > +		/* find the first split flag, and only reassemble then*/
> > > +		while (i < nb_bufs && !split_flags[i])
> > > +			i++;
> > > +		if (i == nb_bufs)
> > > +			return nb_bufs;
> > > +	}
> > > +	return i + fm10k_reassemble_packets(rxq, &rx_pkts[i], nb_bufs - i,
> > > +		&split_flags[i]);
> > > +}